Minimal profile anterior bracket for spinal fixation

ABSTRACT

A spinal fixation device for securing to a spine includes a body having one or more longitudinal members extending between a pair of wedge members. Each wedge member defines one or more openings therethrough for the reception of a bone screw. The wedge members are disposed on opposite ends of the one or more longitudinal members. One of the wedge members is positionable within a first intervertebral space and the other wedge member is positionable within a second intervertebral space. The one or more longitudinal members define a length that spans one or more vertebrae. The one or more longitudinal members are positionable within the one or more vertebrae when the wedge members are positioned within the respective first and second intervertebral spaces to maintain the body in a minimal profile orientation relative to the spine.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/111,198, filed on May 19, 2011, now U.S. Pat. No. 8,647,369, whichclaims the benefit of U.S. Provisional Patent Application No.61/395,875, filed on May 19, 2010, the entire contents of each of whichare hereby incorporated by reference herein.

TECHNICAL FIELD

The present disclosure relates to spinal fixation and, moreparticularly, to anterior brackets for providing support andstabilization to the spinal column and for inhibiting expulsion of aninterbody implant disposed within an intervertebral space.

BACKGROUND

The human spinal column is a complex system of bones and connectivetissues that provides support for the human body and protection for thespinal cord and nerves. The adult spine is comprised of an upper andlower portion. The upper portion contains 24 discrete bones, which aresubdivided into three areas including 7 cervical vertebrae, 12 thoracicvertebrae, and 5 lumbar vertebrae. The lower portion is comprised of thesacral and coccygeal bones. The vertebrae, or vertebral bodies,progressively increase in size from the upper portion downwards to thelower portion.

An intervertebral disc along with two posterior facet joints cushion anddampen the various translational and rotational forces exerted upon thespinal column. The intervertebral discs are spacers located betweenadjacent vertebral bodies, while the facets provide stability at theposterior portions of adjacent vertebrae.

The spine is a flexible structure capable of a large range of motion.There are various disorders, diseases and types of injury, however,which restrict the range of motion of the spine or interfere withimportant elements of the nervous system. These include, but are notlimited to, scoliosis, kyphosis, excessive lordosis, spondylolisthesis,slipped or ruptured discs, degenerative disc disease, vertebral bodyfracture, and tumors. Persons suffering from any of the above conditionsmay experience extreme or debilitating pain and oftentimes experiencediminished nerve function.

Spinal fixation apparatuses are widely employed in surgical processesfor correcting spinal injuries and diseases. When an intervertebral dischas degenerated to the point of requiring removal, there are a varietyof interbody implants that are utilized to take the place of the discsuch as PEEK interbody spacers, metal cages and cadaver and human boneimplants. In order to facilitate stabilization of these interbodyimplants, additional implants are commonly employed. For example,longitudinally linked rods may be secured to coupling elements which, inturn, are secured to bone by spinal bone fixation fasteners, e.g.,pedicle screws, hooks, etc.

As an alternative to using rods, plate and screw systems may be employedto stabilize and secure the anterior or lateral portion of the spine. Inone approach, an interbody implant is placed between the vertebrae and asubstantially flat plate is positioned across the intervertebral spaceand secured to the face of each adjacent vertebral body to inhibitexpulsion of the interbody implant. This approach maximizes the fusiongraft material that can be placed between the vertebrae, and maximizesthe surface area contact between the interbody implant and the adjacentvertebra.

Nonetheless, soft tissue and vasculature limit space for plate and screwsystems adjacent the spine. Therefore, there is a continuing need forproviding stability to the spine while preventing expulsion of aninterbody implant positioned between adjacent vertebrae of the spinewithout impeding upon soft tissue and vasculature. Currently availableon the market are a number of low profile or “zero profile” anteriorspinal implants and fixation devices for application to the anterioraspect of the cervical and/or the lumbar spinal segments. Examplesinclude the Synthes “ZeroP” anterior cervical cage and plate combinationfor use in the cervical spine and the Synthes “SynFix” anterior lumbarcage and plate combination for use in the lumbar spine. However, theseand other similarly designed implants are dedicated to use at a singlesegment. Should the need exist for a low profile implant to be appliedat two levels, two of these separate and distinct implants would need tobe employed. Thus, it is desirable to have an implant that can spanacross two or more disc spaces while maintaining the desired advantagesassociated with a zero profile or low profile relative to the anteriorlimits of the disc spaces and/or the anterior limits of the vertebralbodies.

SUMMARY

Accordingly, a system for securing a spinal fixation device to a spineis disclosed. The system includes one or more bone screws and a spinalfixation device. The one or more bone screws may be formed of a firstmaterial and at least a portion of the spinal fixation device may beformed of a second material. The first and second materials are selectedto enhance securement of the one or more bone screws to the spinalfixation device.

The spinal fixation device includes a body having a pair of longitudinalmembers extending between a pair of wedge members. The body isdimensioned to resist deforming forces including one or both of flexionextension forces and axial compression forces extending through thebody.

The pair of wedge members is disposed on opposite ends of the pair oflongitudinal members. One of the wedge members is at least partiallypositionable within a first intervertebral space of the spine and theother wedge member is at least partially positionable within a secondintervertebral space of the spine. One or both of the wedge members isat least partially wedge shaped. Each wedge member defines one or moreopenings therethrough for the reception of one or more bone screws. Oneor both of the wedge members may define two or more openingstherethrough for the passage and reception of a bone screw in eachopening. One or more openings are disposed at an angle relative to ananterior surface of the body in order to facilitate the securement ofthe bone screw to another vertebra adjacent one of the first or secondintervertebral spaces.

The pair of longitudinal members defines a length that spans one or morevertebra of the spine. The longitudinal members are positionable withina recess defined within the one or more vertebrae. The pair oflongitudinal members is at least partially positionable within the oneor more vertebra when the pair of wedge members is positioned within therespective first and second intervertebral spaces to maintain the bodyin a minimal profile orientation relative to the spine. The one or morelongitudinal members may be positioned even with or substantially evenwith an anterior surface of the one or more vertebrae. Alternatively,the one or more longitudinal members may be recessed below an anteriorsurface of the one or more vertebrae.

In one aspect, a method of securing a spinal fixation device to ananterior portion of a spine includes providing a spinal fixation devicehaving a body including one or more longitudinal members extendingbetween a pair of wedge members. The method involves forming one or morerecesses within one or more vertebrae of the spine, positioning the oneor more longitudinal members at least partially within the one or morerecesses, positioning one of the wedge members at least partially in afirst intervertebral space of the spine, positioning the other wedgemember at least partially in a second intervertebral space of the spine,and securing the spinal fixation device to the anterior portion of thespine so that the spinal fixation device is in a minimal profileorientation relative to the anterior portion of the spine.

The method may include forming the one or more recesses along aplurality of contiguous vertebrae of the spine and positioning the oneor more longitudinal members at least partially within the one or morerecesses along each of the plurality of contiguous vertebrae. One partof the procedure may include securing each wedge member to a secondvertebra of the spine with one or more bone screws, the second vertebrabeing adjacent the one or more vertebrae. The method may involvespanning the one or more longitudinal members along a plurality ofvertebrae. One part of the procedure may include positioning the one ormore longitudinal members within the one or more recesses in a zeroprofile orientation relative to the anterior portion of the spine. Themethod may involve positioning the one or more longitudinal memberswithin the one or more recesses in a low profile orientation relative tothe anterior portion of the spine.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure are described herein withreference to the accompanying drawings, wherein:

FIG. 1 is a front view of a spinal fixation system shown secured to aspine in accordance with the principles of the present disclosure;

FIG. 2 is a cross-sectional view of FIG. 1 taken along section line A-A;

FIG. 3 is a perspective view of a spinal fixation device in accordancewith the present disclosure;

FIG. 4 is a side view of the presently disclosed spinal fixation deviceof FIG. 3;

FIG. 5 is a rear view of the presently disclosed spinal fixation deviceof FIGS. 3 and 4.

DETAILED DESCRIPTION

Various embodiments of the present disclosure will now be described indetail with reference to the drawings, wherein like reference numeralsidentify similar or identical elements. In the drawings and in thedescription that follows, the term “proximal,” will refer to the end ofa device or system that is closest to the operator, while the term“distal” will refer to the end of the device or system that is farthestfrom the operator. In addition, the term “cephalad” is used to indicatea direction toward a patient's head, whereas the term “caudad” indicatesa direction toward the patient's feet. Further still, the term “medial”indicates a direction toward the middle of the body of the patient,whilst the term “lateral” indicates a direction toward a side of thebody of the patient (i.e., away from the middle of the body of thepatient). The term “posterior” indicates a direction toward thepatient's back, and the term “anterior” indicates a direction toward thepatient's front. In the following description, well-known functions orconstructions are not described in detail to avoid obscuring the presentdisclosure in unnecessary detail.

Turning now to FIG. 1, a spinal fixation system is provided inaccordance with the present disclosure and is generally identified byreference numeral 10. Spinal fixation system 10 includes a spinalfixation device 100 and a plurality of bone screws 200 for securing thespinal fixation device 100 to a spine in a minimal profile orientationrelative to an anterior surface “VA” of one or more vertebrae “V.” Thebone screws 200 may be formed of a first material such as titanium alloy(e.g., Ti-6AL-4V) and at least a portion of the spinal fixation device100 may be formed of a second material (e.g., commercially puretitanium). Nonetheless, the first and/or the second material may beformed from any suitable material including, but not limited to,commercially pure titanium, titanium alloys, cobalt chrome alloys, PEEK,stainless steel and the like materials. The first and second materialsare selected to enhance securement of the bone screws 200 to the spinalfixation device 100. In this regard, one of the first and secondmaterials may be softer than the other to provide enhanced resistance tobacking out of the bone screw 200 from the spinal fixation device 100.One example of this combination of materials is described in U.S. Pat.No. 6,322,562 to Wolter, the entire contents of which are incorporatedherein by reference.

With continued reference to FIG. 1, spinal fixation device 100 may beformed as a single, monolithic piece, or may be constructed using anysuitable method for joining the components thereof. As will be describedin greater detail below, spinal fixation device 100 is configured forpositioning at least partially within first and second intervertebralspaces “S1”, “S2 and one or more vertebral bodies of the vertebrae “V”of a patient for providing stabilization and support to the spine in aminimal profile orientation. The spinal fixation device 100 may be usedto inhibit expulsion of an interbody implant “I” positioned within anintervertebral space “S” such as intervertebral spaces “S1”, “S2”,and/or “S3.”

Referring now to FIGS. 3-5, spinal fixation device 100 includes a body102 having an anterior surface 102 a and a posterior surface 102 b. Thebody 102 includes a pair of longitudinal members including first andsecond longitudinal members 110 a, 110 b extending between a pair ofwedge members including first and second wedge members 120 a, 120 b. Thebody 102 may be dimensioned to resist deforming forces. Moreparticularly, the first and second longitudinal members 110 a, 110 b andthe first and second wedge members 120 a, 120 b may haveanterior-posterior dimensions in excess of medial-lateral dimensions, orvice versa, to optimally dispose the mass of material and efficientlyresist one or both of flexion extension forces and axial compressionforces extending through the body 102. This optimization of dimensionsmay alter the inertia of the body 102. With brief reference to FIGS. 1and 2, the body 102 may be dimensioned to have a low profile orientationor zero profile orientation relative to an anterior surface “VA” of theone or more vertebrae “V” when secured to a spine as will be describedin greater detail below.

As best depicted in FIGS. 3 and 5, the first and second wedge members120 a, 120 b are disposed on opposite ends of the first and secondlongitudinal members 110 a, 110 b. Illustrated in FIG. 1, each of thefirst and second wedge members 120 a, 120 b are intradiscal. Morespecifically, the first wedge member 120 a is at least partiallypositionable within the first intervertebral space “S1” and the secondwedge member 120 b is at least partially positionable within the secondintervertebral space “S2.” One or both of the wedge members 120 a, 120 bmay be at least partially wedge shaped, as viewed in lateral profilebest shown in FIG. 4, and may be oriented at any suitable angle and haveany suitable dimensions to accommodate various patient geometries andpatient dimensions. In embodiments, wedge members 120 a, 120 b may haveany suitable shape (including any suitable geometry and/or dimension)for positioning, at least partially, within one or more of theintervertebral spaces “S.” With reference again to FIGS. 3 and 5, eachof the first and second wedge members 120 a, 120 b defines one or moreopenings 122 therethrough for the reception of the one or more bonescrews 200. One or both of the wedge members 120 a, 120 b may define twoor more openings 122 therethrough for the passage and reception of abone screw 200 in each opening. The openings 122 are disposed at anangle relative to an anterior surface 102 a and/or posterior surface 102b of the body 102 and include a lip 124 in order to facilitate thesecurement of a bone screw 200 to another vertebra adjacent one of thefirst or second intervertebral spaces “S1”, “S2.” For example, asillustrated in FIGS. 1 and 2, a first bone screw 200 a secures the firstwedge member 120 a to adjacent vertebra “V3” when the first wedge member120 a is positioned in intervertebral space “S1.” Similarly, a secondbone screw 200 b secures the second wedge member 120 b to adjacentvertebra “V4” when the second wedge member 120 b is positioned inintervertebral space “S2.” As best depicted in FIG. 2, the first andsecond bone screws 200 a, 200 b are positioned at an angle commensuratewith the angle of the openings 122. The openings 122 may be positionedat any suitable angle to accommodate various dimensions and geometriesof the vertebrae of various patients. In this regard, the bone screws200, when inserted into the openings 122, engage the spinal fixationdevice 100 to secure the spinal fixation device 100 to the spine.

Illustrated best in FIG. 1, the first and second longitudinal members110 a, 110 b define a length that intraosseously spans one or morevertebra “V” of the spine and may have any suitable dimension and/orgeometry (including differing dimensions and/or geometries along thelength of one or both of the first and second longitudinal members 110a, 110 b). In FIG. 1, the first and second longitudinal members 110 a,110 b are shown spanning first and second vertebrae “V1”, “V2” andintervertebral space “S3” while the first and second wedge members 120a, 120 b are secured in the first and second intervertebral spaces “S1”,“S2.” The first and second longitudinal members 110 a, 110 b arepositioned within a first recess “R1” and a second recess “R2” definedwithin the first and second vertebrae “V1”, “V2.” The first and secondrecesses “R1”, “R2” may be cut longitudinally along a path havingdimensions and/or geometry sufficient to accommodate one of the firstand second longitudinal members 110 a, 110 b. More particularly, thefirst and second recess “R1”, “R2” may be cut into the vertebral bodiesof the first and second vertebrae “V1”, “V2”, or any number of vertebrae“V” (including a single vertebra “V”) commensurate with the dimensions(e.g., length, width, height, etc.) and/or geometry of the first and/orsecond longitudinal members 110 a, 110 b, by any suitable bone cuttingdevice such as a jig.

As discussed above, the first and second longitudinal members 110 a, 110b are at least partially positionable within the respective first andsecond recess “R1”, “R2” of the one or more vertebra “V” when the firstand second wedge members 120 a, 120 b are positioned within therespective first and second intervertebral spaces “S1”, “S2” to maintainthe body 102 in a minimal profile orientation (e.g., low or zero profileorientation) relative to the spine. In this regard, the first and secondwedge members 120 a, 120 b are recessed into the first and secondintervertebral spaces “S1”, “S2” while the first and second longitudinalmembers 110 a, 110 b are recessed into the first and second recesses“R1”, “R2” to maintain the anterior surface 102 a of the body 102 inclose relationship, e.g., even with or below (zero profile), orsubstantially even with (low profile), the anterior surface “VA” of theone or more vertebrae “V.” More specifically, a zero profile is achievedwhen the first and second longitudinal members 110 a, 110 b (e.g.,length and/or width and/or height) are even with (e.g., flush) or belowthe anterior surface “VA” of the one or more vertebrae “V” along atleast a portion of the one or more vertebrae “V.” In this respect, thefirst and second longitudinal members 110 a, 110 b may be positionedpartially/entirely even with or recessed below the anterior surface “VA”of the one or more vertebrae” to have a zero profile orientation.Similarly, a low profile is achieved when the first and secondlongitudinal members 110 a, 110 b (e.g., length and/or width and/orheight) are substantially even with (e.g., slightly offset from) theanterior surface “VA” of the one or more vertebrae “V” along at least aportion of the one or more vertebrae “V.” In this respect, the first andsecond longitudinal members 110 a, 110 b may be partially or entirelysubstantially even with the anterior surface “VA” of the one or morevertebrae” to have a low profile orientation. The low profileorientation may be within millimeters of the anterior surface “VA” ofthe one or more vertebrae “V.”

In operation, an interbody implant “I” may be positioned betweenadjacent vertebrae “V1” and “V2” of a patient, e.g., during a spinalfusion procedure. Next, one or more jigs or other known bone cuttingdevices may be used to cut the recesses “R1” and “R2” (low or zeroprofile) within one or more of the vertebrae “V”, depending on thedimensions and/or geometry of the spinal fixation device 100 and thenumber of vertebrae “V” and/or spinal discs and/or interbody implantswhich require support. Next, spinal fixation device 100 is inserted fromthe anterior side of the spine so that the posterior surface 102 b ofthe spinal fixation device 100 is adjacent the anterior surface “VA” ofthe one or more vertebrae “V” in a low or zero profile orientation. Asdiscussed above, the spinal fixation device 100 may be dimensioned tospan across one or more vertebrae “V” (e.g., between two or moreintervertebral disc spaces). For example as illustrated in FIGS. 1 and2, where the spinal fixation 100 spans a pair of adjacent vertebrae “V”(e.g., across three intervertebral disc spaces “S1, “S2”, and “S3”), thefirst and second wedge members 120 a, 120 b are recessed into the firstand second intervertebral spaces “S1”, “S2” while the first and secondlongitudinal members 110 a, 110 b are recessed into the first and secondrecesses “R1”, “R2.” More particularly, the first and second wedgemembers 120 a, 120 b may be at least partially disposed into respectiveintervertebral spaces “S1”, “S2” such that each of the first and secondwedge members 120 a, 120 b are substantially abutting respectiveadjacent vertebrae. The first wedge member 120 a may be in abutment withcephalad vertebra “V3” and caudad vertebra “V1” while second wedgemember 120 b is in abutment with cephalad vertebra “V2” and caudadvertebra “V4.” In this manner, the first and second longitudinal members110 a, 110 b are recessed into respective recesses “R1”, “R2” definedalong the vertebrae “V1” and “V2.” In one embodiment, where the spinalfixation device 100 is dimensioned to span across a single vertebra,e.g., vertebra V1, and between two intervertebral disc spaces, e.g.,intervertebral spaces “S1” and “S3”, the first wedge member 120 a may bein abutment with cephalad vertebra “V3” and caudad vertebra “V1” whilesecond wedge member 120 b is in abutment with cephalad vertebra “V1” andcaudad vertebra “V2.” In this embodiment, the first and secondlongitudinal members 110 a, 110 b are recessed into respective recesses“R1”, “R2” defined along the vertebra “V1.”

As can be appreciated, the substantially wedge-shaped configuration offirst and second wedge members 120 a, 120 b permits first and secondwedge members 120 a, 120 b to be inserted various distances into therespective intervertebral spaces “S1” and “S2”, e.g., to achieve adesired spacing between the respective adjacent vertebrae such asadjacent vertebrae “V3”, “V1” and “V2”, “V4” and/or to achieve a desiredposition relative to the interbody implant “I.” In particular, whererelatively small spacing between the adjacent vertebrae is desired,first and second wedge members 120 a, 120 b are advanced a relativelyshort distance into the intervertebral spaces “S.” On the other hand,where a relatively larger spacing is desired, first and second wedgemembers 120 a, 120 b may be advanced further into the intervertebralspaces “S.” The depth of advancement of the first and/or second wedgemember 120 a, 120 b may be commensurate with the depth of the recesses“R1”, “R2” to establish a low or zero profile orientation relative tothe anterior surface “VA” of one or more vertebrae “V.” It is alsocontemplated that the presently disclosed fixation device 100 may besecured to the spine without an implant “I” positioned in anintervertebral space “S” such as intervertebral space “S3.”

Advantageously, because spinal fixation device 100 is not attached tothe interbody implant “I”, the relative positions of the implant “I” andthe spinal fixation device 100 may be adjusted independently of oneanother (and/or relative to one another). The ability to adjust therelative position of the spinal fixation device 100 relative to theinterbody implant “I”, and the fact that the fixation device may bedisposed partially within and partially outside the two or moreintervertebral spaces, e.g., intervertebral spaces “S1” and “S2”advantageously provides the surgeon flexibility with respect to the sizeand position of the implant “I” that can be placed between the vertebrae“V.”

Once spinal fixation device 100 is positioned as desired, a bone screw200 may be inserted into spinal fixation device 100 though each of theopenings 122. For example, two bone screws 200 are advanced through theopenings 122 of the first wedge member 120 a and then driven into thecephalad vertebra “V3” while two more bone screws 200 are advancedthrough openings 122 of the second wedge member 120 b and driven intothe caudad vertebra “V4” so that the spinal fixation device 100 issecured in position. The heads of the bone screws 200 may be configuredto deform lips 124 (FIG. 3) of openings 122 to facilitate the securementof the bone screws 200 therein. As can be appreciated, where aninterbody implant “I” is inserted, the spinal fixation device 100inhibits the expulsion of the interbody implant “I” when secured to thespine.

It will be understood that various modifications may be made to theembodiments of the present disclosure. Therefore, the above descriptionshould not be construed as limiting, but merely as exemplifications ofembodiments. Those skilled in the art will envision other modificationswithin the scope and spirit of the present disclosure.

What is claimed is:
 1. A method of securing a spinal fixation device toan anterior portion of a spine, comprising: providing the spinalfixation device having a body including two longitudinal membersextending between a pair of wedge members; forming two recesses withinat least one vertebra of the spine; positioning the two longitudinalmembers at least partially within the two recesses; positioning a firstone of the pair of wedge members at least partially in a firstintervertebral space defined between adjacent end faces of adjacentvertebrae of the spine; positioning a second one of the pair of wedgemembers at least partially in a second intervertebral space definedbetween adjacent end faces of adjacent vertebrae of the spine; andsecuring the spinal fixation device to the anterior portion of the spineso that the spinal fixation device is in a minimal profile orientationrelative to the anterior portion of the spine.
 2. The method of claim 1,further including: forming the two recesses along a plurality ofcontiguous vertebrae of the spine; and positioning the two longitudinalmembers at least partially within the two recesses along each of theplurality of contiguous vertebrae.
 3. The method of claim 1, furtherincluding securing at least one of the pair of wedge members to at leastone second vertebra of the spine with at least one bone screw, the atleast one second vertebra being adjacent to the at least one vertebra.4. The method of claim 1, further including spanning the twolongitudinal members along a plurality of vertebrae.
 5. The method ofclaim 1, further including positioning the two longitudinal memberswithin the two recesses in a zero profile orientation relative to theanterior portion of the spine.
 6. The method of claim 1, furtherincluding positioning the two longitudinal members within the tworecesses in a low profile orientation relative to the anterior portionof the spine.
 7. The method of claim 1, further including positioningthe two longitudinal members in parallel relation to each other withinthe at least one vertebra of the spine.
 8. The method of claim 1,wherein forming the two recesses includes forming the two recesses inparallel relation to each other.
 9. A method of securing a spinalfixation device to an anterior portion of a spine, comprising: providingthe spinal fixation device having a body including at least onelongitudinal member extending between a pair of wedge members; formingat least one recess within at least one vertebra of the spine;positioning the at least one longitudinal member at least partiallywithin the at least one recess; positioning a first one of the pair ofwedge members at least partially in a first intervertebral space definedbetween adjacent end faces of adjacent vertebrae of the spine;positioning a second one of the pair of wedge members at least partiallyin a second intervertebral space defined between adjacent end faces ofadjacent vertebrae of the spine; positioning the second one of the pairof wedge members longitudinally offset from the first one of the pair ofwedge members; and securing the spinal fixation device to the anteriorportion of the spine so that the spinal fixation device is in a minimalprofile orientation relative to the anterior portion of the spine. 10.The method of claim 9, further including: forming the at least onerecess along a plurality of contiguous vertebrae of the spine; andpositioning the at least one longitudinal member at least partiallywithin the at least one recess along each of the plurality of contiguousvertebrae.
 11. The method of claim 9, further including securing atleast one of the pair of wedge members to at least one second vertebraof the spine with at least one bone screw, the at least one secondvertebra being adjacent to the at least one vertebra.
 12. The method ofclaim 9, further including spanning the at least one longitudinal memberalong a plurality of vertebrae.
 13. The method of claim 9, furtherincluding positioning the at least one longitudinal member within the atleast one recess in a zero profile orientation relative to the anteriorportion of the spine.
 14. The method of claim 9, further includingpositioning the at least one longitudinal member within the at least onerecess in a low profile orientation relative to the anterior portion ofthe spine.
 15. The method of claim 9, wherein forming the at least onerecess within the at least one vertebra of the spine includes formingtwo recesses within the at least one vertebra, and wherein positioningthe at least one longitudinal member at least partially within the atleast one recess includes positioning two longitudinal members at leastpartially within the two recesses.
 16. The method of claim 15, furtherincluding positioning the two longitudinal members in parallel relationto each other within the at least one vertebra of the spine.
 17. Themethod of claim 15, wherein forming the two recesses includes formingthe two recesses in parallel relation to each other.